CAREER: Post-transcriptional regulation of mRNA stability in Mycobacterium smegmatis

该项目的目标是了解细菌如何适应压力条件，如缺乏营养或氧气。众所周知，细菌能够改变自己的生理机能，以便在不利条件下生存，但这究竟是如何发生的，我们还不太清楚。这项工作将探索细菌如何激活某些基因并停止使用其他基因，以保存能量以应对压力。因为细菌在许多方面影响着人类的生活——通过塑造我们的环境，影响我们的健康，以及作为研究和工业的重要工具——这项研究的结果应该具有深远的科学影响。此外，该项目将为研究生和本科生提供宝贵的培训机会，他们将直接参与实验室和课程设置的研究。通过开发工具和技术作为平台，使当地高中学生和他们的教师参与实验室的动手研究和研究结果的计算分析，将扩大教育影响。将开发一个教授基因调控的教育模块，并向服务于贫困社区的高中传播。转录物丰度的调节对细菌应激反应至关重要，可能发生在转录点或降解点。对mRNA稳定性和功能的转录后调控的贡献知之甚少，特别是在分枝杆菌中，分枝杆菌与更常见的研究细菌在RNA代谢方面不同。以耻垢分枝杆菌为模式生物，该项目的目标是：(i)确定转录后调控对转录物丰度和应激功能的影响；（ii）确定在应力诱导的生长抑制过程中全局稳定mRNA的机制；（iii）确定分枝杆菌mRNA降解机制的一些核心成分的作用和调控。该方法将结合转录组学、遗传学、生物化学和建模来测量mRNA的切割和降解，并测试关于这些过程的调节和表型后果的假设。这项工作将为分枝杆菌mRNA稳定性的决定因素和转录后调控对应激反应的贡献提供基础知识。从长远来看，整合转录和转录后机制的信息有望导致对使分枝杆菌在不同环境中如此成功的应激耐受性机制的全面理解。

The goal of this project is to understand how bacteria adapt to stressful conditions, such as lack of nutrients or oxygen. Bacteria are known to be able to modify their physiology in order to survive in under adverse conditions, but exactly how this occurs is not well-understood. This work will explore how bacteria activate certain genes and stop using others in order to conserve energy in response to stress. Because bacteria affect human lives in many ways--by shaping our environment, influencing our health, and serving as important tools for research and industry--the results of this study should have far-reaching scientific impacts. In addition, this project will provide valuable training opportunities for graduate and undergraduate students, who will participate directly in the research in both laboratory and course-based settings. Educational impact will be broadened by developing tools and techniques as a platform for involving local high school students and their teachers in hands-on research in the lab and in computational analyses of research results. An educational module for teaching gene regulation will be developed and disseminated to high schools that serve underprivileged communities. Regulation of transcript abundance is critical to bacterial stress response, and can occur at the point of transcription or at the point of degradation. The contribution of post-transcriptional regulation of mRNA stability and function is poorly understood, particularly in mycobacteria, which differ from more commonly studied bacteria with respect to RNA metabolism. Using Mycobacterium smegmatis as a model organism, the objectives of this project are to (i) determine the impact of post-transcriptional regulation on transcript abundance and function in response to stress; (ii) identify mechanisms that globally stabilize mRNA during stress-induced growth inhibition; and (iii) define the roles and regulation of some of the central components of the mycobacterial mRNA degradation machinery. The approach will combine transcriptomics, genetics, biochemistry, and modeling to measure mRNA cleavage and degradation and test hypotheses about the regulation and phenotypic consequences of these processes. This work will generate foundational knowledge about the determinants of mRNA stability in mycobacteria and the contributions of post-transcriptional regulation to stress response. In the longer term, integration of information on transcriptional and post-transcriptional mechanisms is expected to lead to a comprehensive understanding of the stress tolerance mechanisms that render mycobacteria so successful in diverse environments.